In Cornouaille, in a Brittany bordered by the ocean, Martin has a string of odd jobs and meager larceny. He has recently been dating Gwen, a lonely girl who goes swimming every day on the high seas, in all weather. When Gwen announces to Martin that she is pregnant with him and that she wants to keep the child, he gets scared and disappears. Corinne, Martin’s sister, has trouble getting Jean, her husband, to accept the arrival of a third child, already struggling with professional problems. While Martin and Jean go adrift, Gwen and Corinne struggle alone. Until the day Martin is accused of murder.